From: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Date: Sun, 7 Jun 2015 20:40:11 +0000 (+0200)
Subject: drm/nouveau/pm: prevent freeing the wrong engine context
X-Git-Tag: v4.2-rc5~14^2~3^2~7
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3693d544056b822f7f2454da5acb7eda9471b902;p=karo-tx-linux.git

drm/nouveau/pm: prevent freeing the wrong engine context

This fixes a crash when multiple PM engine contexts are created.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
---

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
index 2006c445938d..274457ca3fef 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
@@ -332,9 +332,12 @@ static void
 nvkm_perfctx_dtor(struct nvkm_object *object)
 {
 	struct nvkm_pm *ppm = (void *)object->engine;
+	struct nvkm_perfctx *ctx = (void *)object;
+
 	mutex_lock(&nv_subdev(ppm)->mutex);
-	nvkm_engctx_destroy(&ppm->context->base);
-	ppm->context = NULL;
+	nvkm_engctx_destroy(&ctx->base);
+	if (ppm->context == ctx)
+		ppm->context = NULL;
 	mutex_unlock(&nv_subdev(ppm)->mutex);
 }